vc7 debug下没有错，release下出错，高手看看怎么回事

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VwSend.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
VwTabAddress.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
VwTabServer.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
PgeConfirm.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
PgeFinish.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
VwAddress.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
VwPerson.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
DlgPlan.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
DlgPost.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
DlgReply.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
NewTreeListCtrlView.obj : error LNK2019: unresolved external symbol __imp__PlaySoundA@12 referenced in function "public: void __thiscall CNewTreeListCtrlView::ResetScrollBar(void)" (?ResetScrollBar@CNewTreeListCtrlView@@QAEXXZ)
Communication.obj : error LNK2019: unresolved external symbol __imp__PlaySoundA@12 referenced in function "void __cdecl DownloadAddress(class CSocksifiedSocket * *)" (?DownloadAddress@@YAXPAPAVCSocksifiedSocket@@@Z)
DlgDy.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
DlgGroup.obj : error LNK2001: unresolved external symbol __imp__PlaySoundA@12
DlgLogon.obj : error LNK2019: unresolved external symbol __imp__PlaySoundA@12 referenced in function "public: void __thiscall CDlgLogon::OnBnClickedBtnLogon(void)" (?OnBnClickedBtnLogon@CDlgLogon@@QAEXXZ)
.\Release/Client.exe : fatal error LNK1120: 1 unresolved externalsBuild log was saved at "file://j:\work\Client\Release\BuildLog.htm"
Client - 16 error(s), 0 warning(s)